This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 116 |
| 6 | 642 |
| 7 | 3938 |
| 8 | 26194 |
| 9 | 186042 |
| 10 | 1395008 |
| 11 | 10948768 |
| 12 | 89346128 |
| 13 | 754062288 |
| 14 | 6553942722 |
| 15 | 58457558394 |
| 16 | 533530004810 |
| 17 | 4970471875914 |
| 18 | 47169234466788 |
| 19 | 455170730152340 |
| 20 | 4459456443328824 |
| 21 | 44300299824885392 |
| 22 | 445703524836260400 |
| 23 | 4536891586511660256 |
| 24 | 46682404846719083048 |
| 25 | 485158560873624409904 |
| 26 | 5089092437784870584576 |
| 27 | 53845049871942333501408 |